1. Field of the Invention
The invention relates to an electrolyte composition, and more particularly, to an electrolyte composition containing a specific anion and a lithium battery using the electrolyte composition.
2. Description of Related Art
In recent years, the market demand for a secondary lithium battery capable of repeatingly charging and discharging and having the features of, for instance, lightweight, high voltage value, and high energy density has rapidly increased. In particular, the lithium battery has very high potential in the application and expandability of light electric vehicles, electric vehicles, and the large power storage industry. As a result, current performance requirements for the lithium battery such as lightweight, durability, high voltage, high energy density, and high safety have also become higher.
In a secondary lithium battery, an electrolyte solution containing lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), or lithium hexafluoroantimonate (LiSbF6) is generally used. However, the compounds are readily dissolved at high temperature, thereby producing a Lewis acid. The Lewis acid damages the structures of, for instance, the cathode material, the anode material, the solid electrolyte interface, and the isolation film in the secondary lithium battery, thus causing poor structural stability, performance degradation, and reduced charge-discharge cycle life of the secondary lithium battery. Therefore, how to increase the structural stability of the secondary lithium battery when operating at high temperature is one of the desired goals of those skilled in the art.